1xe2x80x94Field of the Invention
The present invention relates to a sealing and acoustic insulation panel, in particular for automobile vehicle doors, the panel including a synthetic plastic material sealing sheet and a layer of acoustic insulation, generally of a fibrous material, for example, wadding consisting of fine tangled fibers of synthetic plastic material.
2xe2x80x94Description of the Prior Art
In the prior art, a panel of this type is glued to a support plate such as the inner metal skin of a door by means of a bead of glue deposited on the free face of the sealing sheet and protected by a silicone-coated or similar paper strip. When the panel is used, the protective paper strip is removed, the panel is applied to the support plate at the required location, and a roller is passed over the free face of the panel, i.e. over the layer of acoustic insulation, over the strip of glue, to press it down well and therefore to glue the panel properly to the support panel.
An embellisher panel, such as a door trim panel, is then fixed, for example clipped, to the support, with the sealing panel between the support plate and the trim panel.
The above prior art technique has drawbacks for automobile manufacturers, as they have to obtain separate supplies of the sealing and acoustic insulation panels and the door trim panels, their stock control procedures have to cover two stocks of panels, and at assembly time the sealing and acoustic insulation panel must first be fixed to the support plate, after which the roller is applied to the required place on the panel, as already indicated, after which the trim panel is clipped to the support plate.
It has been proposed to simplify and reduce the cost of this assembly procedure firstly by supplying a one-piece assembly comprising the sealing and acoustic insulation panel already in position on the trim panel, which one-piece assembly is fixed to the support plate in one operation. As in the prior art, a bead of glue has been deposited onto the free face of the sealing sheet to glue the sealing and acoustic insulation panel to the support plate, and it is the elasticity of that panel when compressed between the support plate and the trim panel that is deemed to press the bead of glue sufficiently strongly onto the support plate.
Serious gluing defects are encountered in practice, however, due to insufficient elasticity of the layer of acoustic insulation, which has only a very low resistance to compression when it is made from fibers that have a very small diameter, in order to have a good acoustic insulation capacity, and which still has too low a resistance to compression even when it is formed of larger diameter fibers, to increase its elasticity, although this is to the detriment of its acoustic insulation capacity.
One particular object of the present invention is to provide a simple, effective and low-cost solution to the above problem.
The invention proposes a sealing and acoustic insulation panel, in particular for automobile vehicle doors, said panel including a synthetic plastic material sealing sheet and a layer of acoustic insulation, for example, a layer of fibrous material, wherein said panel is associated with a semi-rigid synthetic plastic material bearing frame that extends over a free face of said layer of acoustic insulation in line with a bead of adhesive material deposited on a free face of said sealing sheet for fixing said panel to a support plate such as a door inner skin.
The bearing frame, which extends along the bead of adhesive material on the other side of the sealing and acoustic insulation panel enables pressure to be applied effectively to the bead of adhesive when an embellisher panel, such as a door trim panel, is fixed to the support plate by appropriate means, the bearing frame being disposed between the sealing and acoustic insulation panel and the trim panel and bearing on the trim panel.
In a particular embodiment of the invention, the frame is made from an expanded synthetic plastic material, for example, in expanded polypropylene, and preferably in expanded polypropylene balls and is shaped by molding.
The polypropylene balls are preferably expanded and bonded together in the mold in which the bearing frame is made.
According to another feature of the invention, the sealing and acoustic insulation panel, the frame and the embellisher panel form a sub-assembly which is mounted on said support in a single operation.
The trim panel is clipped or screwed to said support at the same time as said sealing and acoustic insulation panel is glued to said support.
Generally speaking, the invention simplifies the operations that must be effected on an assembly line, in particular an automobile vehicle door assembly line, reduces the number of such operations, and reduces the assembly, procurement and storage costs incurred by automobile manufacturers.
The invention will be better understood and other features, details and advantages of the invention will become more clearly apparent after reading the following description, which is given by way of example and with reference to the accompanying drawings.